MAPPING OF A NEW TARGET REGION OF ALLELIC LOSS TO A 2-CM INTERVAL AT 22Q13.1 IN PRIMARY BREAST-CANCER

Allelic losses on chromosome arm 22q are frequently observed in human meningiomas and in carcinomas of the colon, ovary, and breast. Among 1 40 primary breast cancers we examined for loss of heterozygosity (LOH) at 16 polymorphic loci on the long arm of chromosome 22, 56 (40%) sho wed LOH for at least one locus. Eleven of these tumors had retained he terozygosity for markers proximal to the NF2 locus but showed LOH for markers distal to NF2. Deletion mapping indicated a new common region of deletion, 2-cM in extent, at q13.1 between Interleukin 2 receptor b eta (IL2RB) and D22S279, Our results raise the possibility that one or more tumor suppressor genes associated with breast cancer may exist a t 22q13.1. Comparison of these results with clinicohistological data i ndicated that allelic losses on 22q tend to occur more frequently in t umors of malignant histological types. (C) 1998 Wiley-Liss, Inc.